1. Field of the Invention
The present invention relates to a portable measuring apparatus for an enzyme sensor, for example.
2. Description of the Related Art
In a prior art portable measuring apparatus (see:JP-A-7-159366), a sensor holder for holding a planar type enzyme sensor is fixed at an end of a main body. In order to prevent the sensor from being dried during a non-operation mode, a cap for encapsulating preserving liquid is fitted onto the sensor holder. In this case, the cap is constructed by a cone-shaped liquid bag and a packing member. Therefore, the sensor holder is dipped into preserving liquid by inserting the sensor holder through a slit portion of the packing member into the cone-shaped liquid bag.
In the above-described prior art portable measuring apparatus, however, since the packing member is not flexible, when the sensor holder is attached to the cap or detached from the cap, the leakage of preserving liquid through the slit portion thereof cannot be suppressed. Also, when the sensor holder is attached to the cap or detached from the cap, the pressure within the cap remarkably fluctuates which may disperse preserving liquid and break down the enzyme sensor.
It is an object of the present invention to provide a portable measuring apparatus capable of suppressing leakage of preserving liquid from a cap as well as suppressing the dispersal of preserving liquid and the break down of a sensor.
According to the present invention, in a portable measuring apparatus, a sensor holder for holding a sensor is fixed at an end of a main body, and a fitting member is fixed at the end of the main body. The fitting member has a groove formed on its outer periphery. A cap for encapsulating preserving liquid is provided and has a protrusion corresponding to the groove.
Also, at least one axial groove leading to the groove is provided, so that air leaks from the cap to the groove and vice versa.